Manta Ray Nursery Discovered off the Coast of Texas

A graduate student at Scripps Institution of Oceanography at the University of California San Diego and colleagues from NOAA’s Office of National Marine Sanctuaries have discovered the world’s first known manta ray nursery. Located in the Gulf of Mexico off the coast of Texas at NOAA’s Flower Garden Banks National Marine Sanctuary, the juvenile manta ray habitat is the first of its kind to be described in a scientific study.

Joshua Stewart, a marine biology Ph.D. candidate at Scripps and lead author of the study, observed the juvenile mantas while conducting research on manta population structure at Flower Garden Banks, one of 15 federally designated underwater areas protected by the Office of National Marine Sanctuaries.

“The juvenile life stage for oceanic mantas has been a bit of a black box for us, since we’re so rarely able to observe them,” said Stewart, who also serves as executive director of the Manta Trust, a global manta conservation program. “Identifying this area as a nursery highlights its importance for conservation and management, but it also gives us the opportunity to focus on the juveniles and learn about them. This discovery is a major advancement in our understanding of the species and the importance of different habitats throughout their lives.”

Known as the gentle giants of the sea, oceanic manta rays ( Mobula birostris ) are large, plankton-eating rays that live in the open ocean and can reach sizes of up to 7 meters (23 feet) in wingspan as adults. Oceanic mantas are typically found in subtropical and tropical waters around the world with aggregation sites commonly found far from coastal areas, making their populations hard to access and study. For this reason, major knowledge gaps remain in their basic biology, ecology, and life history. Baby mantas are virtually absent from nearly all manta populations around the world, so even less is known about the juvenile life stage.